Method and apparatus for centrifugal casting



April 7, 1925.

J. B. LADD METHOD AND APPARATUS FOR GENTRIFUGAL CASTING Filed Nov. 28, 1922 5 Sheets-Sheet l mamy April Z 1925.

J. B. LADD METHOD AND APPARATUS FOR GENTRIFUGAL CASTING Filed Nov. 28, 1922 5 Sheets-Sheet 2 A fr0/MH April 7, 1925.

. J; B. LA DD IETHOD AND APPARATUS FOR CENTRIFUQAL CASTING Filed Nov. 28, 1922 5 Sheets-Sheet 3 April 7, 192.5. 1,532,537

J..B. LADD METHOD AND APPARATUS FOR CENTRFUGAL CASTING Filed Nov. 2s, 1922 5 sheets-sheet 4' J. B. LADD limon Anni-APPARATUS Fon` cENTRlIFuaAL CASTING April 7,1925. y "52,531

.Filed Nov. 28 1922 5 Sheets-Sheet 5 A TT OHNE Y Patented Apr. 7, 1925.

PATENT OFFICE.

.'rAMEs B. LADD, or AEDMoEE, PENNSYLVANIA, AssieNon To NITED sTATEs CAST IRON PIPE a roUNnEY COMPANY, or BURLINGTON, NEW JERSEY, A CORPORA- TION 0F NEW JERSEY.

METHOD AND APPARATUS FOR CENTRIFUGAL CASTING'.`

Application led November 28,u 1922. Serial No. 603,756.

To all whom it may concern.'

.Bev it known that I, JAMES B. LADD, a citizen of the United States of America, and .resident of Ardmore, county .of Montgomery, State of Pennsylvania, have invented certain new and useful Improvements in Methods and Apparatus for Centrifugal Casting, of which the following is a true and exact description, yreference being had to the accompanying drawings, which form a part thereof.

My invention relates to an improved method of making centrifugal castings and to improvements in apparatus especially adapted for use in practising the said invention but capable of use in other methods of making centrifugal castings.

It has heretofore been proposed to use sec tional molds for the casting of pipes and similar tubular castings with a special view of casting ipes with bell` and bead ends which could) not be extracted from a solid mold. It has also been proposed in the construction of molds of this character vto make up a portion' of the mold in which the bead end of the pipe, for instance, is cast, of a collapsible construction offmolding sand so that the contraction of the casting in cooling will not result in breaking the casting. The object of my new method of casting pipes is to enable me to cast a bell and bead end pipe -in a segna-intel mold and under conditions which will enable me to cast bead end pipes in molds having no collapsible or yielding sections.

The object of the mechanical part of. my

invention is to provide improved mechanism especially adapted for use in carrying my new Mmethod into practice but also adapted for use to a highly benefici-al extent in the constructio-n of any centrifugal molding apparatus in which it is necessary tov use a longitudinally divided segmental mold.

The nature of my invention both in its -method and mechanlcal features will be best explained in connection with the drawings which illustrate my improved apparatus as constructed especially for use by my improved method and in which- Figure 1 is a sectional elevation of my improved centrifugal casting machine with the parts in the position in which a pipel has just been cast.

mold in the casing.

left hand end of the apparatus in the posi- A tion of the part shown in Fig. 1.

Figure 5 is a similar enlarged detail view of the right hand end of the apparatus inthe position of the part shown in Fig. 2.

Figure 6 is an end elevation of the apparatus as shown in Fig. 5.

Figure 7 is a cross sectional view on the line 7-7 of Fig. 1, looking toward the left.

Figure 8 is a cross sectional view on the v line 8 8 of Fig. 1, looking toward the right. Figure 9 is a cross sectional view taken on the line 9-9 of Fig. 1, looking toward the right.

Figure 10 is a cross sectional view on the line 10-10 of Fig. 1, and j Fi ure 11 is a detail view illustrating the angu ar positions of the mold sectors and casing during the operation of inserting the A indicates the framing on which the machine is supported and which supports at its top tracks indicated at B, B, on which the mold sustaining yapparatus moves backward and forward preferably on an incline, as shown. C is a power cylinder supported on the framing A and C a piston rod extending from the aiston, not shown, and 'connected with aownwardly extendin lug E* of the casing section E. D is a brac (et supported on the frame Ahaving at its top a tubular head indicated at D in which is adjustably supported a stop indicated at D2 the purpose of which will be hereafter explained. E, E', are respectively the lower and upper sections of a divisional casing having inwardly turned flanged ends as indicated at E2, E2. From the sidesof this casing extend brackets indicated at E, E", for supporting the wheels indicated at G, see Fi 10, which wheels rest' upon the tracks 135,11, see Fig. 9, indicate remov able sections of the casing section E on which are supported the rollers indicated at H, H, which in turn support the rotatable casing I. F, F, indicate packing rings for making a tight joint between the casing E, E', and the rotatable casing I so that the space enclosed between the casings E, Il, and I, .may be used as a water jacket for cooling the casing I and the ,parts in contact with it.

The casing I, as shown, is provided with a multiple series of inwardly projecting wedge shaped lugs indicated at I, these on the casing section Ilnand connected by.

gears indicated at J engaging the gear wheel I2. J2 indicates an electric brake for stopping the action of the motor and parts driven by it when the current is cut oit' from. the motor.

K, K, etc., indicate the several segments, three, as shown, making up the segmental lnold. These segments are provided with outwardly extending lugs indicated at K with inclined wedge surfaces adapted to contact with the inclined lugs I of the easing I and, in the construction illustrated, force the mold sectors together when the sectors are moved toward the left relatively to the casing I. L, L, are under-cut wedge pieces shaped to lit in the under-cut recesses I2 of the casing I and secured to the ends of the mold sectors by bolts L and, to permit the under-cut wedge pieces I2 to be properly assembled at the left hand side of the machine, the openings I4 are formed in the casing I so that the undercut pieces L can be inserted, after the mold sectors are assembled in the'casing I, and secured in place by screw bolts L inserted through these openings. k, 7c', are respectively circular and longitudinal slots formed on the outside of the sectors K for the purpose of making these sectors more flexible and insure that they will fit properly together when pressed together by the inter-acting wedge lugs. K3 is a seat formed inthe left hand end of the mold sectors to receive the core iron M which supports the core N for the bell end of the pipe. K4, as best shown in Fig. 5, indicates the annular recess at the right hand, end ofthe mold segments for the casting of the bead on the end of the pipe. M 1s a core ironV for supporting the core for the bell end .of the pipe, this core, indicated at N,

being supported on the portion M of the core iron and the core iron having a central boss indicated at M2 which is located in alignment with the stop D2. The core iro-n is secured to one of the mold sectors bya bolt as indicated at Ml and is readily removable from the end of the mold. 'I indicates the runner through which melted metal is run into the mold and, as shown, is provided with a lip indicated at T for directing the metal downward into the mold. U indicates the casting formed in the mold. U', Fig. 3, indicates a freshly poured portion of the casting when made by the process of pouring indicated in Fig. 3. W indicates the line wire by which the electric current is fed to the motor through the roller indicated at W.

In assembling the apparatus the segmental mold is inserted in the casing I as indicated in Fig. 11 and is then turned so that its wed e lugs K will come into the operative position with regard to the wedge lugs I. As shown in Fig. 10', when 1n proper angular relation, the under-cut wedge pieces L are secured to the mold sectors and inserted in the under-cut recesses I2 of the casing I, these pieces securing each mold sector in roper angular positlon to the casing I an also so securing the parts together that movement of the 'mold sectors with reference to the casing I toward the right results in an outward radial movement of the sectors while a reversed longitudinal movement moves the sectors together and, in connection with the intermediate lugs K and I', clamps the sectors tightly to ether, the flexibility of the sectors broug t about by the slots la, c, insuring that their edges can be forced into tight contact with each other.

Preparatory to casting a pipe in the mold the mold sectors are moved toward the left then the mold is moved by the cylinder and l piston indicated lat C, toward the left and, the mold being in full rotation through the action of the motor J, the metal is laid in the moving mold in spiral coils, the casting beine* thus progressively formed as indicated in Fig. 3, and the cooling and hardening of the castin r bein preferably accelerated by the coollne e ect of Water in the water Jacket formed between the casings E,

lim

E' andV I, drawing heat from the mold through the contact points between the contacting wedge lugs and the mold sectors on the casing I, so that the metal is not only progressively laid into the mold but is progressively cooled therein so that the metal at the left hand end of the mold will rogilessively cool, harden and contract w ile t e metal progressively fed to the mold towards its right hand end is still fluid, the result of which, obviously, is that such contraction as occurs in the casting during the progressive pouring of the metal exerts no disruptive strain on the casting and is fully compensated for by the flow of the fluid metal and these conditions are maintained during the entire pouring of the casting until and after the metal enters the ortion K of the mold which forms the bea at the end of the pipe. But obviously, any contraction in the casting. which occurs after the soliditication of the metal forming the bead would tend to disrupt the casing and it is of the essence of my method invention that the mold sectors should be moved apart to release the bead immediately on the solidiication of the metal forming the bead and before such further contraction in the casting takes place as would tend to disrupt 1t. This o ening of the mold sectors I automatically provide for'by thel adjustment of the stopy D2 which, immediately after the casting of the bead, comes in contact with the boss M2 of the core iron M and causes a thrust 0n the se mental mold which holds it in position while the casing I continues to move toward the under-cut wedge pieces L movethe mold sectors ra idly outward to the osition indicated in igs.'.2 and 5, releasing the bead and permitting the casting to contract as indicated in Fig. 5.

Immediately .on or contemporaneously with the outward movement of the mold sectors, current is cut ofi' from themotor and the brake brought into action, stopping the` rotative movement of the motor and of themold and thereafter the core iron M is removed, the cast pipe withdrawn from the mold, mold sectors again clamped-together and the new pipe cast.

A metallic' mold which is exposed to the direct contact with molten metal must have considerable thickness of walls vandwhere the mold is made up of segments the segments are liable to distortion from strains arising from 4rapid heating and cooling.

i When distorted the edges of the segments will not normally fit together and, owing to the thickness of the segments they are not sufiiciently flexible to be forced into contact.

In my pending applications filedJuly 12, 1922, Serial Numbers 574,469 and 574,470, I have described as a' means for vdiminishing disruptive strains in 'solid pipe molds the left with the effect that the with a segmental mold outer or inner and outer surfaces of themolds and in making up segmental molds I have discovered that the slotting of the mold segments will not only diminish disruptive strains butr will make the segments sufliciently flexible to be forced into contact with each other even when distorted while, at the same time, preserving the necessary wallv thickness of the segments.

While, as shown and described, my im-` proved machine is especially designed for the casting of pipes by the method above described it will be obvious that it embodies many novel features of construction which are capable of use in connection with collapsible or yielding molds for the casting of the bea'd end of the pipe and in another a plication filed November 29, 1922, Serial o. 603,757, I have described` and claimed the combination of a similar segmental mold and mold actuating mechanism with a yielding and collapsib e mold section -in which the bead is cast.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is: 1. 'A centrifugal casting apparatus coinprising a rotatable casing in combination with a segmental mold'and means connecting the mold segments with the casing and whereby the segments can be moved radially towards and from the center line of the mold.

2. A centrifugal casting apparatus comprising a rotatable casing in combination with a segmental mold and means connecting the mold segments with the casing and whereby the segments are moved in and out in radial planes when shifted longitudinally in the casing.

3. A centrifugal casting apparatus comprising a rotatable casing in combination and interengagcd inclined surfaces connecting the mold segments with the casing whereby the mold l segments are moved in and out in radial planes when shifted longitudinally in the casino'.` f

4. centrifugal casting apparatus comprising arotatable casing having inwardly extending inclined bearings for the mold segments in combination with a segmental mold the segments of which are provided withl inclined bearings adapted to co-act with the bearing of the casing to lock the moldsegments together when the mold is moved lon itudinally in one direction and to permit t e' segments to separate when the mold is` moved in the other direction.

5. A centrifugal casting apparatus comprising a rotatable casing in combinationv with a segmental mold, interengaged inclined surfaces connecting the mold se ments with the casngwhereby the mo d up of longitudinal segments longitudinally and circumferentially slotted te increase their flexibility.

8. A centrifugal mold for castinv made up of longitudinal segments-externa ly slotted to increase their fiexibility.

9. A centrifugal casting apparatus comprising a rotatable casing in combination with a segmental mold, the segments of which are slotted to increase their Hexibility and means located between the casing and mold for clamping the mold segments together at multiple points along their length.

10. A centrifu al casting apparatus comprising a rotata le casing in combination with a segmental meld, interenga ed inclined surfaces connecting the mo d segments with the casing whereby the meld segments are moved in and out in radial planes when shifted longitudinally in the casing, a series of inclined bearing surfaces formed .in the casing and on the mold segments for clamping the segments to ether along their length and a water jae ret enclosing the rotatable casing.

11. A cent-rife al casting apparatus com prising a rotata le casing in combination with means for moving said casing lon itudinally, a segmental mold located in t e casing and longitudinally movable therein means located between the casing and mold segments for clamping the segments to-v gether when they are moved longitudinally in one direction and means locatedin the path of the moving casing for shifting the mold se them an permit them to move apart.

12. A centrifugal casting apparatus comprising a rotatable casing in combination with means for moving said casing lon itudinally, a segmental mold located in t e casing and longitudinally movable therein, means located between the casing and mold segments 'for clamping the segments together' when they are moved longitudinally in one direction, a bell core ring secured to the end of one of the mold segments and means located in the path of the moving casing ada ted to contract with the core ring and siift the mold segments, to unclamp them andpermit them to move apart.

13. A centrifufal castingr machine com prisiug a rotatable casing having projecting inward therefrom a series of inclined bearing surfaces arran ed in longitudinally running rows with c ear s aces between said rows, in combination wit i a segmental mold each sefrment of which is provided exter nally with one or more rows of inclined bearings extending outwardly and of such breadth that they will pass between two rows ef bearings of the casing to permit the insertion and withdrawal of the mold and means for holding operative position 1n the casing. v

14. In the operation of a centrifugal pipe casting machine com risiner a segmental mold the segments o whic are movable in radial planes and formed when assembled to cast a ipe with bell and bead ends, the method ofp casting which consists in ouring the metal progressively into the mold) beginning at the bell end so that suclr solidilicaents in a direction to uncle-mp the mold segments in tion and contractionof the casting as oecurs before the bead end is solidified can take place without disruptive tendency and moving the mold sectors apart immediately on the solidification of the bead end to relieve the casting of disruptive strains.

JAMES B. LADD. 

